The effects of inflammation on bone cells are not well understood. The work in progress in our laboratory is designed to help elucidate the mechanisms involved in bone loss caused by an inflammatory infiltrate. Our studies involve an ultrastructural examination of two animal models of periodontal disease, and culture fetal long bones stimulated to resorb by prostaglandin and osteoclast-activating factor. The effects of these agents on isolated bone cells are also being examined.